Internal combustion engine



Aug. 3, 1966 F. J. PETRIE 3,267,661

INTERNAL COMBUSTION ENGINE Filed Jan. 19, 1965 COMPRESSOR United StatesPatent 3,267,661 INTERNAL COMBUSTION ENGINE Frank J. Petrie, 80 SpeenSt., Natick, Mass. Filed Jan. 19, 1965, Ser. No. 426,519 9 Claims. (CI.60-15) This invention relates to internal combustion engines and moreparticularly to internal combustion engines of the reciprocating pistontype.

The object of the invention is to provide an improved internalcombustion piston engine which supplies a relatively high andsubstantially constant torque at all engine speeds. A further object ofthe invention is to provide an internal combustion engine with greatlyimproved efiiciency thereby permitting higher power output per unitengine weight and size. A still further object of the invention is toprovide such an improved internal combustion engine at a relatively lowcost and with a simple construction so as to be easily operated andmaintained.

One feature of this invention is the provision in an internal combustionengine of an air supply piston and cylinder assembly which forcibly andcontinuously supplies combustion feeding air to a combustion cylinderthroughout its power stroke thereby insuring gradual and complete fuelcombustion and a steady power output.

Another feature of this invention is the provision of an internalcombustion engine of the above featured type in which the air supplypiston is driven by the combustion piston and the cross sectional areaof the air supply piston is substantially smaller than that of thecornbustion piston thereby establishing a self regulating air supply.

Another feature of this invention is the provision of an internalcombustion engine of the above featured types wherein a gas compressordevice is utilized to supply isothermally compressed air to the airsupply cylinder for subsequent injection into the combustion cylinderthereby greatly increasing the weight of combustion supporting oxygenwhich can be injected into the compression cylinder.

Another feature of this invention is the provision of an internalcombustion engine of the above featured types including a compressed airstorage vessel having a volume substantially greater than the volumedisplaced by one full stroke of the air supply piston connected betweenthe gas compressor and the air supply cylinder thereby insuring a steadyair supply.

Another feature of this invention is the provision of an internalcombustion engine of the above featured types including an exhaustcylinder assembly with a piston which is driven by the expanding gasesexhausted from the combustion cylinder.

Another feature of this invention is the provision of an internalcombustion engine of the above featured type wherein the cross sectionalarea of the exhaust piston is substantially greater than that of thecombustion piston.

These and other objects and features of the present invention willbecome apparent upon a perusal of the following specification taken inconjunction with the accompanying drawing which is a partial, schematic,cross sectional showing of a preferred internal combustion engineembodiment of this invention.

Referring now to the drawing there is shown the primary combustionpiston 10 supported by the rotatable crank shaft 11 so as to allowreciprocal movement within the primary combustion cylinder 12. The upperportion of the primary cylinder 12 is closed by the halfsphere shapedcover 13 through which extend a pair of spark plugs 14. Positioned inthe upper portion of the primary cylinder 12 and mounted from the coverportion 13 is the hollow spherical combustion chamber 15 "ice whichpossesses a plurality of apertures 16. The fuel injection nozzle 17,connected to a source of fuel (not shown), extends through the cover 13and into the interior of combustion chamber 15. The primary intake,

valve 18 and the primary exhaust valve 19 are positioned on oppositesides of the primary cylinder 12 and allow for the passage of gases intoand out of the upper portion thereof.

Adjacent the primary cylinder 12 is the air supply piston 21 which isalso supported by the rotatable crank shaft 11 so as to allow reciprocalmovement within the air supply cylinder 22. The cross sectional area ofsupply piston 21 is one half that of primary piston 10. The primaryintake valve 18 whose stem is slideably supported by the primary baseportion 20 provides a path for gas communication between the upperportion of the air supply cylinder 22 and the upper portion of theprimary cylinder 12. The air supply inlet valve 23 whose push rodextends through and is slideably supported by the air supply housing 24provides a gas conductance path from the air supply housing 24 into theupper portion of the air supply cylinder 22.

Also adjacent the primary cylinder 12 but opposite the air supplycylinder 22 is the exhaust cylinder 25 with the exhaust piston 26 havinga cross sectional area three times that of primary piston 10. Theexhaust piston 26 is similarly supported by the rotatable crank shaft 11so as to permit reciprocal movement Within the exhaust cylinder 25. Theupper portion of exhaust cylinder 25 communicates with the upper portionof primary cylinder 12 via the primary exhaust 'valve 19 whose push rodis slideably supported by the primary base portion 20. Also providing agas flow path into the upper portion of the exhaust cylinder :25 is thefinal exhaust valve 28. The push rod of final exhaust valve 28 extendsthrough and is slideably supported by the bottom wall portion of theexhaust duct 27.

The air supply inlet valve 23, the primary intake valve 18, the primaryexhaust valve 19 and the final exhaust valve 28 are operated by contactof their push rods with one of a plurality of cam mechanisms 29 All ofthe cam mechanisms 29 are mounted for rotation on a single cam shaft 31which is driven by and at the same rotational speed as the crank shaft11 by suitable motion transmitting device (not shown).

The air supply tubulation 33 is connected between the gas compressor 34and the compressed air storage vessel 35. The compressor 34 is aconventional multi-stage type having suitable cooled cylinders, innercoolers and after coolers to provide an isothermal compression of airwhich enters the compressor through inlet opening A. The compressed airstorage chamber 35 is composed of an elongated tube which has beencoiled into a large number of turns 36 thereby providing a vessel ofgreat mechanical strength. The outlet side of the compressed air storagechamber 35 is connected to the interior of air supply chamber 24 by anadditional length of supply tubulation 37.

During operation of the internal combustion engine shown in the drawingatmospheric air enters the compressor 34 through inlet tubulation A andis isothermally compressed. The compressed air is pumped into thecompressed air storage chamber 35 and stored at a desired pressure of,for example, 300 lbs. per sqyin. In certain applications substantiallyhigher pressures may be desired. Dosed quantities of the compressed airthen pass through the tabulation 37 and supply housing 24 into the airsupply cylinder 22 through the supply valve 23 which is automaticallyopened by a cam 29 during the out-stroke of supply piston 21. At the endof the supply piston out-stroke the inlet valve 23 is closed and theprimary intake valve 18 is opened by the cam mechanisms 29. This enablescompressed air from the supply cylinder 22 to enter the upper portion ofprimary cylinder 12 where it mixes with a fine dispersion of suitablefuel supplied by the injection nozzle 17. The fuel and air mixture isignited by the spark plugs 14 producing combustion and expansionthereof. The pressure exerted by the expanding gases causes downwardmovement of the primary piston 1t and rotation of the attached driveshaft 11 which movement is utilized to perform the Work required of theengine.

The rotation of drive shaft 11 also produces an upward movement of thesupply piston 21 insuring a continuous supply of compressed air for theprimary cylinder 12 during the entire work-stroke of primary piston it).Since fuel is also continuously supplied by the injection nozzle 17 acontrolled combustion will take place during the entire out-stroke ofthe primary piston it).

The gas pressure in the primary cylinder 12 during combustion must belower than the gas pressure in supply cylinder 22 if a continuing supplyof combustion inducing oxygen is to be transferred into the primarycylinder 12. Also the expanding gas force exerted against the primarypiston 19 during combustion must be greater than the force exertedagainst supply piston 21 by the compressed air in supply cylinder 22 ifa net operating force is to be exerted on the drive shaft 11. It istherefore highly desirable that the cross sectional area of the primarypiston be substantially larger than the cross sectional area of thesupply piston 21. This allows the maintenance during a power stroke of aslightly lower gas pressure in the primary cylinder 12 than in thesupply cylinder 22 while still providing a substantially greater thruston the primary piston 16 than is exerted against the supply piston 21.

When the primary piston 10 reaches the end of its outstroke a cammechanism 22 opens the primary exhaust valve 19 and hot gas in primarycylinder 12 which is still at relatively high pressure expands throughthe valve 19 into the exhaust cylinder 25. At this time the exhaustpiston 26 is at the top of the cylinder and the expanding gas pressureproduces a downward force on the exhaust piston 26 and a rotationalforce on the drive shaft 11. The exhaust piston 26 is preferably madewith a cross sectional area substantially larger than that of theprimary piston 10. This results in the exertion by the expanding exhaustgases of a significantly larger force on the exhaust piston 26 than onthe primary iston 10 and a net positive rotational force on the driveshaft 11.

Upon completion of the exhaust piston 26 out-stroke the cam mechanisms29 automatically open the final exhaust valve 23 and close primaryexhaust valve 19. The gas contained in exhaust cylinder 25 which is nowpreferably at about atmospheric pressure is exhausted through the finalexhaust valve 28 and the exhaust duct 27 into the atmosphere. Therelatively small power requirement for this exhaust stroke is providedby the 180 degree out of phase combustion stroke of the primary pistonit) through the drive shaft 11.

The isothermal compression by the compressor 34 greatly increases theweight of air which can be injected into the primary combustion cylinder12. The increased quantity of oxygen provided by this air willcorrespondingly support the combustion of a greater quantity of fuelproducing substantially higher heat units for the expanding gases duringthe combustion cycle. For this reason the engine is capable of greatlyincreased power output per unit size and weight. The use of a compressorto establish a given desired weight of air for combustion also rendersthe engine particularly well suited for operation under varyingconditions of ambient pressure or under extremely low pressureconditions such as exist, for example, at high elevations.

Also the low initial temperature of the compressed air introduced intoprimary cylinder 12 will permit lower maximum combustion gastemperatures and lower engine operating temperature thus substantiallyreducing the heat loss normally incurred in conventional hightemperature internal combustion engines. The reduced heat loss in theengine itself will compensate for the energy requirements of thecompressor 34-. Furthermore the engines low operating temperaturepromotes the possibility of multi-fuel consumption such as gasoline,kerosene, etc.; the possibility of operating Without additional air orliquid coolant systems; and the possibility of improved performanceunder extremely cold ambient temperature conditions.

The final exhaust cylinder and piston 25, 26 also increases theefi'iciency 0f the engine by utilizing the energy remaining in the highpressure combustion gas after completion of the primary piston 1t)out-stroke. Thus substantially the full energy content of the fuel canbe utilized to provide useful work. This exhaust cylinder has thefurther advantage of acting as a noise mufiier and thereby eliminatingthe requirement for the non-work producing mufliers conventionally usedwith internal combustion engines.

Thus the present invention provides a novel and greatly improvedinternal combustion engine. The engine while exhibiting high efficiencyand versatility has a relatively simple construction and low cost.

Obviously, many modifications and variations of the present inventionare possible in light of the above teachings.

For example only, while the engine accessories such as the compressor34, the cam mechanisms 29, the supply piston 21, etc., are preferablyoperated directly by the power shaft they can also be coupled or gearedseparately and can be operated at speeds other than that of the powershaft. Also the walls of combustion chamber 15 can be made massiveenough to allow retention of sufficient heat to ignite the fuel mixtureitself thereby eliminating the requirement for the spark plugs 14 aftera certain starting 7 period. Furthermore, While various parts of theapparatus have been described in connection with their utility infurnishing a supply of air to the combustion cylinder, the primary gasrequired for combustion is, of course, oxygen and gas mixtures otherthan air can be utilized. It is, therefore, to be understood that withinthe scope of the appended claims the invention may be practicedotherwise than as specifically described.

What is claimed is:

1. An internal combustion engine apparatus compris- (a) a primary pistonand cylinder assembly,

a drive shaft connected to said primary piston so as to be activatedthereby,

a fuel injection means connected to said primary cylinder and adapted toinject a fine dispersion of fuel thereinto,

an ignition means associated with said primary cylinder and adapted toprovide ignition of the fuel injected into said primary cylinder,

a primary intake valve adapted to supply gas to said primary cylinderand a primary exhaust valve adapted to allow exhaust of combustive gastherefrom;

(b) an air supply cylinder connected for gas communication to saidprimary cylinder through said primary intake valve,

an air supply piston positioned for movement within said air supplycylinder and adapted to force gas from said air supply cylinder intosaid primary cylinder via said primary intake valve,

an air supply inlet valve connected for gas communication with said airsupply cylinder and adapted to supply gas thereto,

an air supply driving means connected to said air supply piston andadapted to provide an instroke thereof during each outstroke of saidprimary piston,

a primary intake valve control means adapted to open said primary intakevalve during the instroke of said air supply piston and to close saidprimary intake valve during the outstroke thereof, and

an air supply inlet valve control means adapted to open said air supplyinlet valve during the outstroke of said air supply piston and to closesaid air supply inlet valve during the instroke thereof.

2. An internal combustion engine apparatus according to claim 1 whereinthe cross-sectional area of said air supply piston is substantially lessthan that of said primary piston.

3. An internal combustion engine apparatus according to claim 1 whereinsaid air supply driving means includes a drive shaft connected to saidprimary piston so as to be driven thereby and mechanical means forproviding positive mechanical actuation of said primary intake valve.

4. An internal combustion engine apparatus according to claim 3 whereinthe cross-sectional area of said air supply piston is substantially lessthan that of said primary piston.

5. An internal combustion engine apparatus comprismg:

(a) a primary piston and cylinder assembly,

a drive shaft connected to said primary piston so as to be activatedthereby,

a fuel injection means connected to said primary cylinder and adapted toinject a fine dispersion of fuel thereinto,

an ignition means associated with said primary cylinder and adapted toprovide ignition of the fuel injected into said primary cylinder,

a primary intake valve adapted to supply gas to said primary cylinderand a primary exhaust valve adapted to allow exhaust of combustive gastherefrom;

(b) a gas compressor means adapted to produce a substantially isothermalcompression of gas to above atmospheric pressure,

air inlet means connected to said gas compressor means and adapted tosupply free air thereto; and

(c) air supply means connected between said gas compressor means andsaid primary intake valve and adapted to provide gas circulation fromsaid gas compressor to said primary cylinder via said primary intakevalve.

6. An internal combustion engine apparatus according to claim 5 whereinsaid air supply means includes:

an air supply cylinder connected for gas communication to said primarycylinder through said primary intake valve,

an air supply piston positioned for movement within said air supplycylinder and adapted to force gas from said oxygen supply cylinder intosaid primary cylinder via said primary intake valve,

an air supply inlet valve connected for gas communication with said airsupply cylinder and adapted to supply gas thereto,

an air supply driving means connected to said air supply piston andadapted to provide an instroke thereof during each outstroke of saidprimary piston,

a primary intake valve control means adapted to open said primary intakevalve during the instroke of said air supply piston and to close saidprimary intake valve during the outstroke thereof, and

an air supply inlet valve control means adapted to open said air supplyinlet valve during the outstroke of said air supply piston and to closesaid oxygen supply inlet valve during the instroke thereof.

7. An internal combustion engine apparatus according to claim 6 whereinsaid air supply driving means includes a drive shaft connected to saidprimary piston so as to be driven thereby and mechanical means forproviding positive mechanical actuation of said primary intake valve.

8. An internal combustion engine apparatus according to claim 7 whereinthe cross-sectional area of said air supply piston is substantially lessthan that of said primary piston.

9. An internal combustion engine apparatus according to claim 6 whereinsaid air supply means also includes a compressed air storage containerconnected between said gas compressor mean and said air supply cylinderand wherein the volume of said compressed air storage container issubstantially greater than the volume displaced by a full stroke of saidair supply piston.

References Cited by the Examiner UNITED STATES PATENTS 651,062 6/1900Adamson 15 1,138,938 5/1915 Davison 60-15 2,018,914 10/1935 Endres123119 2,020,224 11/1935 Waseige 123-119 FOREIGN PATENTS 1,781 2/1888Great Britain.

EDGAR W. GEOGHEGAN, Primary Examiner.

1. AN INTERNAL COMBUSTION ENGINE APPARATUS COMPRISING: (A) A PRIMARYPISTON AND CYLINDER ASSEMBLY, A DRIVE SHAFT CONNECTED TO SAID PRIMARYPISTON SO AS TO BE ACTIVATED THEREBY, A FUEL INJECTION MEANS CONNECTEDTO SAID PRIMARY CYLINDER AND ADAPTED TO INJECT A FINE DISPERSION OF FUELTHEREINTO, AN IGNITION MEANS ASSOCIATED WITH SAID PRIMARY CYLINDER ANDADAPTED TO PROVIDE IGNITION OF THE FUEL INJECTED INTO SAID PRIMARYCYLINDER, A PRIMARY INTAKE VALVE ADAPTED TO SUPPLY GAS TO SAID PRIMARYCYLINDER AND A PRIMARY EXHAUST VALVE ADAPTED TO ALLOW EXHAUST OFCOMBUSTIVE GAS THEREFROM; (B) AN AIR SUPPLY CYLINDER CONNECTED FOR GASCOMMUNICATION TO SAID PRIMARY CYLINDER THROUGH SAID PRIMARY INTAKEVALVE, AN AIR SUPPLY PISTON POSITIONED FOR MOVEMENT WITHIN SAID AIRSUPPLY CYLINDER AND ADAPTED TO FORCE GAS FROM SAID AIR SUPPLY CYLINDERINTO SAID PRIMARY CYLINDER VIA SAID PRIMARY INTAKE VALVE, AN AIR SUPPLYINLET VALVE CONNECTED FOR GAS COMMUNICATION WITH SAID AIR SUPPLYCYLINDER AND ADAPTED TO SUPPLY GAS THERETO, AN AIR SUPPLY DRIVING MEANSCONNECTED TO SAID AIR SUPPLY PISTON AND ADAPTED TO PROVIDE AN INSTROKETHEREOF DURING EACH OUTSTROKE OF SAID PRIMARY PISTON, A PRIMARY INTAKEVALVE CONTROL MEANS ADAPTED TO OPEN SAID PRIMARY INTAKE VALVE DURING THEINSTROKE OF SAID AIR SUPPLY PISTON AND TO CLOSE SAID PRIMARY INTAKEVALVE DURING THE OUTSTROKE THEREOF, AND AN AIR SUPPLY INLET VALVECONTROL MEANS ADAPTED TO OPEN SAID AIR SUPPLY INLET VALVE DURING THEOUTSTROKE OF SAID AIR SUPPLY PISTON AND TO CLOSE SAID AIR SUPPLY INLETVALVE DURING THE INSTROKE THEREOF.